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- ID:
- ivo://CDS.VizieR/J/A+A/379/564
- Title:
- Vega-type and PMS stars UBVRI photo-polarimetry
- Short Name:
- J/A+A/379/564
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This table presents optical UBVRI broadband photo-polarimetry of the EXPORT sample obtained at the 2.5m Nordic Optical Telescope. The database consists of multi-epoch photo-polarimetry of 68 pre-main-sequence and main-sequence stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/339/701
- Title:
- Velocities and BR photometry in LMC
- Short Name:
- J/MNRAS/339/701
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a large spectroscopic survey of the LMC, consisting of more than 1300 radial velocities measured accurately with the 2dF instrument during three observing compaigns 1999-2002. In this sample, no evidence is found for any extraneous, kinematically distinct population over the expected LMC and Galactic components. We discuss the significance of this finding for the LMC self-lensing models. The sample was randomly selected from three APM photographic plates with 16<=R<=18mag and -1.0<=Bj-R<=2.5mag. The fields were centered on previous microlensing events. The 1200V grating was used with 1.1{AA} per pixel resolution over 4625-5765{AA}. The zero point of the velocity of LMC K-type stars is set by cross-correlating with a K-type standard star. For sample stars of other spectral type we assume no systematic change of the peak of velocity distribution with spectral type.
- ID:
- ivo://CDS.VizieR/J/AJ/133/1041
- Title:
- Velocities and CMT2 photometry in globular M92
- Short Name:
- J/AJ/133/1041
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the determination of high-accuracy radial velocities for 306 members of the globular cluster M92 using the Hydra multiobject spectrograph on the WIYN telescope. We have concentrated on stars outside of the central region of the cluster, located up to 14.4' from the cluster center. Candidate members were selected for spectroscopy based on a photometric metallicity index determined from three-band Washington photometry, also obtained with the WIYN telescope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/1625
- Title:
- Velocities and photometry in NGC 2112
- Short Name:
- J/MNRAS/386/1625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a new, wide-field (20x20arcmin^2^), multicolour (UBVI), photometric campaign in the area of the nearby old open cluster NGC 2112. At the same time, we provide medium-resolution spectroscopy of 35 (and high-resolution of additional 5) red giant and turn-off stars. This material is analysed with the aim to update the fundamental parameters of this traditionally difficult cluster, which is very sparse and suffers from heavy field star contamination. Among the 40 stars with spectra, we identified 21 bona fide radial velocity members which allow us to put more solid constraints on the cluster's metal abundance, long suggested to be as low as the metallicity of globulars. As indicated earlier by us on a purely photometric basis, the cluster [Fe/H] abundance is slightly supersolar ([Fe/H]=0.16+/-0.03) and close to the Hyades value, as inferred from a detailed abundance analysis of three of the five stars with higher resolution spectra. Abundance ratios are also marginally supersolar. Based on this result, we revise the properties of NGC 2112 using stellar models from the Padova and Yale-Yonsei groups.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A94
- Title:
- Velocities and photometry in Trumpler 20
- Short Name:
- J/A+A/561/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Trumpler 20 is an old open cluster (OC) located toward the Galactic centre, at about 3kpc from the Sun and ~7kpc from the Galactic centre. Its position makes this cluster particularly interesting in the framework of the chemical properties of the Galactic disc because very few old OCs reside in the inner part of the disc. For this reason it has been selected as a cluster target of the Gaia-ESO Survey, and spectra of many stars in the main sequence and red clump phases are now available. Moreover, although it has been studied by several authors in the past, no consensus on the evolutionary status of Tr 20 has been reached. The heavy contamination of field stars (the line of sight of Tr 20 crosses the Carina spiral arm) complicates the correct interpretation. Another interesting aspect of the cluster is that it shows a broadened main sequence turn-off and a prominent and extended red clump, characteristics that are not easily explained by classical evolutionary models. Exploiting both spectroscopic information from the Gaia-ESO Survey (and the ESO archive) and literature photometry, we obtain a detailed and accurate analysis of the properties of the cluster. We make use of the first accurate metallicity measurement ever obtained from several spectra of red clump stars, and of cluster membership determination using radial velocities. According to the evolutionary models adopted, we find that Tr 20 has an age in the range 1.35-1.66Gyr, an average reddening E(B-V) in the range 0.31-0.35mag, a distance modulus (m-M)_0_ between 12.64 and 12.72mag. The spectroscopic metallicity is [Fe/H]=+0.17dex. We discuss the structural properties of the object and constrain possible hypotheses for its broadened upper main sequence, by estimating the effect of differential reddening, and its extended red clump.
- ID:
- ivo://CDS.VizieR/J/ApJ/649/201
- Title:
- Velocities and Washington photometry in Carina dSph
- Short Name:
- J/ApJ/649/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new large-area Washington M, T2+DDO51 filter survey of more than 10deg^2^ around the Carina dSph galaxy reveals a spectroscopically confirmed power-law radial density break population of Carina giant stars extending several degrees beyond the central King profile. Magellan telescope MIKE spectroscopy establishes the existence of Carina stars to at least 4.5 times its central King limiting radius, rlim, and primarily along Carina's major axis. To keep these stars bound to the dSph would require a global Carina mass-to-light ratio of M/L>=6300(M/L)_{sun}}. The MIKE velocities, supplemented with ~950 additional Carina field velocities from archived VLT+GIRAFFE spectra with r<~rlim, demonstrate a nearly constant Carina velocity dispersion (sigma_v_) to just beyond r=rlim and both a rising and a velocity shear at still larger radii. Together, the observational evidence suggests that the discovered extended Carina population represents tidal debris from the dSph.
- ID:
- ivo://CDS.VizieR/J/A+A/485/95
- Title:
- Velocities of F-G-K stars in Blanco 1
- Short Name:
- J/A+A/485/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby open cluster Blanco 1 is of considerable astrophysical interest for formation and evolution studies of open clusters because it is the third highest Galactic latitude cluster known. It has been observed often, but so far no definitive and comprehensive membership determination is readily available. An observing programme was carried out to study the stellar population of Blanco 1, and especially the membership and binary frequency of the F5-K0 dwarfs. We obtained radial-velocities with the CORAVEL spectrograph in the field of Blanco 1 for a sample of 148 F-G-K candidate stars in the magnitude range 10<V<14. New proper motions and UBVI CCD photometric data from two extensive surveys were obtained independently and are used to establish reliable cluster membership assignments in concert with radial-velocity data. The membership of 68 stars is confirmed on the basis of proper motion, radial velocity, and photometric criteria. Fourteen spectroscopic- and suspected binaries (2 SB2s, 9 SB1s, 3SB?) have been discovered among the confirmed members. Thirteen additional stars are located above the main sequence or close to the binary ridge, with radial velocities and proper motions supporting their membership. These are probable binaries with wide separations. Nine binaries (7 SB1 and 2 SB2) were detected among the field stars. The spectroscopic binary frequency among members is 20% (14/68); however, the overall binary rate reaches 40% (27/68) if one includes the photometric binaries. The cluster mean heliocentric radial velocity is +5.53+/-0.11km/s based on the most reliable 49 members. The Vsini distribution is similar to that of the Pleiades, confirming the age similarities between the two clusters.
- ID:
- ivo://CDS.VizieR/J/AJ/147/150
- Title:
- Velocities of globular clusters in M104
- Short Name:
- J/AJ/147/150
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combining our own past measurements and velocity measurements obtained from the literature, we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24kpc or ~5R_e_), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41kpc or ~9R_e_). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that M/L_V_ increases from 4.5 at the center to a value of 20.9 at 41kpc (~9R_e_ or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20kpc (~4R_e_or ~7.4') to the mass computed from X-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples.
- ID:
- ivo://CDS.VizieR/J/AJ/156/300
- Title:
- Velocity and light curve analysis of three PPNe
- Short Name:
- J/AJ/156/300
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained contemporaneous light, color, and radial velocity data for three proto-planetary nebulae (PPNe) over the years 2007 to 2015. The light and velocity curves of each show similar periods of pulsation, with photometric periods of 42 and 50 days for IRAS 17436+5003, 102 days for IRAS 18095+2704, and 35 days for IRAS 19475+3119. The light and velocity curves are complex with multiple periods and small, variable amplitudes. Nevertheless, at least over limited time intervals, we were able to identify dominant periods in the light, color, and velocity curves and compare the phasing of each. The color curves appear to peak with or slightly after the light curves while the radial velocity curves peak about a quarter of a cycle before the light curves. Similar results were found previously for two other PPNe, although for them the light and color appeared to be in phase. Thus, it appears that PPNe are brightest when smallest and hottest. These phase results differ from those found for classical Cepheid variables, where the light and velocity differ by half a cycle, and are hottest at about average size and expanding. However, they do appear to have similar phasing to the larger-amplitude pulsations seen in RV Tauri variables. Presently, few pulsation models exist for PPNe, and these do not fit the observations well, especially the longer periods observed. Model fits to these new light and velocity curves would allow masses to be determined for these post-AGB objects, and thereby provide important constraints to post-AGB stellar evolution models of low- and intermediate-mass stars.
